<!doctype html>
<meta charset=utf-8>
<title>CSS Animations on view transition pseudos run more than once</title>
<link rel="help" href="https://drafts.csswg.org/css-animations-1/">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../css-animations/support/testcommon.js"></script>
<style>
:root::view-transition,
:root::view-transition-group(root),
:root::view-transition-image-pair(root),
:root::view-transition-old(root),
:root::view-transition-new(root) {
    animation: view-transition-animation 1ms;
}
@keyframes view-transition-animation {
    to { opacity: 0 }
}
</style>
<div id="log"></div>
<script>
"use strict";
promise_test(async t => {
    let viewTransition = document.startViewTransition(() => {});
    await viewTransition.ready;
    assert_equals(document.documentElement.getAnimations({ subtree: true }).length, 5, "Starting a view transition should start related animations.");

    await viewTransition.finished;
    assert_equals(document.documentElement.getAnimations({ subtree: true }).length, 0, "Stopping a view transition should stop related animations.");

    await waitForNextFrame();
    viewTransition = document.startViewTransition(() => {});
    await viewTransition.ready;
    assert_equals(document.documentElement.getAnimations({ subtree: true }).length, 5, "Re-starting a view-transition should restart related animations.");
}, "CSS Animations on view transitions are canceled and restarted when the view transition starts and ends.");
</script>
